Electrostatic headphones (or loudspeakers) have lower mass diaphragms compared with dynamic drivers' heavier cones and domes of "regular" speakers. Domes and cones are propelled by a moving coil from either the center or edge of their diaphragms.

Lucky me, I recently reviewed three of the world's very best headphones, the Audio Technica ATH-W5000, Denon AH-D7000 and Sennheiser HD 800 for Home Entertainment, due in the September issue.

But the advancement of high-end headphones doesn't stand still and now I've heard something even better: The WooAudio WES headphone amplifier and Stax SR-007 Mk2 headphone.

The sound of nothing

Every high-end audio designer strives to make gear that doesn't have a sound per se so the music magically appears, fully formed and real.

But back here on planet earth every CD player, turntable, amplifier, speaker, and headphone I've heard has a sonic signature. They inevitably color the sound, shrink its natural dynamic range, add distortion, and fail to reproduce the full dimensionality of the music.

They can still sound awfully good, but fall far short of producing the illusion of live music.

Headphones never sound believably real, but they have major advantages over speakers, even cost-no-object high-enders priced within spitting distance of a Porsche 911 GT3 or Maserati Quattroporte S.

Ultra-high-end speakers still have to submit to the vagaries of room acoustics anomalies--room reflections, reverberation, standing waves, and ambient noise--that take their toll in a multitude of ways.

Headphones leapfrog all of that, there's nothing between the headphone and your ears. And headphones, even edge of the art ones live in a more attainable section of the high-end universe. The cost of true greatness ain't cheap, but it's a tiny fraction of the MSRP of the very best speaker based systems.

Which brings us to the WooAudio WES Electrostatic Headphone Amplifier and Stax SR-007 Mk2 electrostatic headphone.

Stax headphones use a very different operating principle than dynamic headphones (pretty much every headphone from lowly ear buds to the very best full size headphone are dynamic designs).

Stax are different, they have been making electrostatic headphones since 1960 in Japan, and their current flagship model, the SR-007 Mk2 is what I'm using with the Woo WES headphone amplifier. The Stax SR-007 Mk2 isn't new, it premiered in 2007, but the WES is.

Stax electrostatic headphone prices start at $380 for the SR-202 'phones (Woo also offers the GES tube amp for Stax headphones that runs $1,450). The WES is a completely different design and will also work with Sennheiser Orpheus electrostatic headphones.

Electrostatic headphones (or loudspeakers) have lower mass diaphragms compared with dynamic drivers' heavier cones and domes of "regular" speakers. Domes and cones are propelled by a moving coil from either the center or edge of their diaphragms.

Electrostatic drivers generate force and pressure evenly over the diaphragm so it's not as prone to resonances and breakup distortion as dynamic drivers. For a full detail, check out Wiki's article .

The SA-31MK is an upgrade from Vincent's SA-31. The output stage has two 6N16 vacuum tubes. The final output stage uses two more of the same tubes and functions in a pure Class A mode. The SA-31MK is analog only and features six RCA style inputs, and one record out.